Constantine's Silver Medallion: Ticinum, 315

I was doing a search for a specific silver medallion of Constantine struck in 315 and, surprisingly to me, the third google result was apost from here from a few years ago, in which I quoted Averil Cameron as follows:

Like other Christian signs, the chi-rho emblem is in fact rare on Constantine's coins, and the early silver medallions of 315 from Ticinum (Pavia) showing the Emperor wearing a high-crested helmet with the Christogram are exceptional.

As it turns out, the medallion referred to there was the one I was looking for today, from here:

What is interesting about this one especially is the chi-rho on the helmet, and the traditional she-wolf suckling the twins in the bottom right on the shield.